


Day Nineteen

by FellQueen (Nikasha)



Series: Kinktober 2019 [19]
Category: Undertale (Video Game)
Genre: Assisted Suicide, Gun Kink, Gunplay, M/M, Object Insertion, Wall Sex
Language: English
Status: Completed
Published: 2019-10-30
Updated: 2019-10-30
Packaged: 2021-01-13 05:41:01
Rating: Explicit
Warnings: Major Character Death
Chapters: 1
Words: 2,001
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21239075
Author URL: https://archiveofourown.org/users/Nikasha/pseuds/FellQueen
Summary: Day NineteenPrompt: Gun playPairing: DustKiller (Dust!Sans/Killer!Sans)





	Day Nineteen

**Author's Note:**

> Here’s a day I missed!
> 
> Originally it wasn’t going to have character death, but then the characters kind of did their own thing.

Killer rapped his knuckles on the table, staring blankly off into space. The pattern was staccato and changed rhythm occasionally as it suited his whim, with brief pauses when he got tired of the noise. Which was often. Everything was just tiring.  
There was a shift behind him, time and space shifting to make room.  
“Oh, Killer! Just who I was looking for.” The words were lilting, unhinged.  
Dust, then. He turned to look over his shoulder. “Sup?”  
Dust was rocking back and forth on his heels, hands hidden behind his back. “Brought something from another universe~ Something fun.”  
Killer raised a brow. “Fun?” He had some doubts about what Dust considered ‘fun.’ Last time it had been a severed leg. Horror had stolen it and Killer liked to pretend he didn’t know what happened after that.  
Dust glanced around then held up a finger to his teeth. “You gotta promise not to tell Nightmare. Okay?”  
Killer was almost positive that Nightmare already knew, but his curiosity was piqued. “Alright. I won’t.” He steadfastly avoided the actual promising part.  
Judging by how his grin widened, Dust noticed, but he didn’t comment. He brought his other hand from behind his back, something shiny, dark, and rounded in his grasp.  
Killer blinked. “A gun. Did you get that from mobtale?”  
“Something like that.” Dust shrugged. “Got some bullets, too. Wanna play with it?”  
Killer’s instinctive answer was absolutely not. That thing in the hands of a lunatic sounded like a recipe for disaster. But then the darkness kicked back in and he shrugged. “Yeah, alright. What kind of game?”  
Dust laughed softly. It was almost creepier than his giggles. He pointed the barrel between Killer’s eyes. “You’ll figure it out.”  
Killer swallowed. Nihilism or no, having death pointed at his face was chilling. “Uh—“  
Dust pulled the gun away. He reached forward and grabbed Killer by the back of his neck, pressing a searing kiss to his mouth. When Killer opened his mouth to gasp, surprised, Dust shortcut them to another location.  
It took Killer a moment to get his bearings, thrown off by the kiss and sudden transport. Dust was still kissing him, making it hard to focus, but judging by the bedspread and familiar gouges in the walls, Dust had taken them back to his room. Surprising, considering most of the time Dust tended to stay back in his own timeline in his own house. Ghosts haunted him like a plague, after all.  
Dust pushed him into the wall and Killer flinched. He pushed at Dust’s shoulders, growling, but Dust just stumbled a step back and latched onto him again. Killer grunted as he was shoved bodily against the wall, Dust’s form pressing up against him as teeth found his neck.  
Killer growled again, hands going to Dust’s hips and tightening. Before he could try anything, he felt something cold click against his temple and his breath hitched.  
A red and blue eyelight flicked up to get a look at him, Dust taking in his expression with a grin. He licked a stripe up Killer’s vertebrae. “My brother says you’re a little crazy. That you killed your whole timeline.”  
Killer’s soul flickered, the red target wavering before solidifying again. “Get your bro out of here,” he rasped, voice unsteady from more than just arousal.  
Dust snorted. “Oh, he isn’t here, duh. He told me this earlier.”  
Killer rumbled uncertainly. “Can we not talk about this shit when you’re trying to get into my pants?”  
Dust snorted, unimpressed. “Fine, spoilsport.” He apparently decided to take that as permission to take liberties, because Killer was suddenly without shorts and his jacket was shoved away from his shoulders. “Can’t fuck unless your sans shorts,” Dust said idly.  
Killer gave a helpless snicker, but hissed and clocked his skull on the wall as cold fingers found his pubic arch. He dug his phalanges into Dust’s hips until they ached.  
Dust giggled. “You’re fun. I wanna keep you.” His fingertips found a sensitive point and dug in harshly.  
Killer yelped and bucked, face screwing up in discomfort. “Fuck, watch it,” he said irritably, catching Dust’s wrist. The gun suddenly cocked right next to his skull and he froze, swallowing.  
Dust just grinned at him.  
“If you’re gonna rape me, I’m calling it quits.” He tried to say it firmly, but his voice shook.  
Dust rolled his eyelights. “Chill out, I don’t wanna do _that._ But pain can be fun, too, pretty boy.” He nudged the gun against Killer’s skull. “Hm I wanna see your eyes bleed.”  
“Wha—“  
Dust took the gun from Killer’s skull down to his pelvis. He slid the cold metal along the curve of his hip then dragged the barrel up his spine, catching it on the ridges and dips and making a slow clattering noise.  
Killer shuddered, locking up. He really didn’t trust Dust not to shoot him for kicks. The threat was leaving a sweet burn on his tongue and in his pelvis.  
Dust gave him a quick kiss, all teeth. “You gonna leak for me?”  
He probably hadn’t meant that to sound raunchy, but Killer reacted like he had, shivering and taking a short inhale. His magic was rapidly building, but he was a little hesitant to let it drop into place.  
Dust noticed. Because of course he did. “Cute,” he purred next to Killer’s skull. He pushed the gun up into his pelvis, scraping the inside carelessly.  
Killer jerked, gritting his teeth against the pain. “Can’t you be a little gentler,” he started and cut off into a ragged groan when Dust grabbed his tailbone.  
“Maybe.” Dust licked his teeth. “Let go already, I’m getting bored.”  
Bored Dust was about ten times worse than amused Dust. He tended to do weird shit to entertain himself. Killer let his magic finally fall into place, convulsively pulling Dust closer to him as his cunt tightened around the barrel of the gun. It was still cold, but he was rapidly warming it up.  
Dust licked his cheek and Killer realized his eyes had started to ooze. Still in thin lines for now, not the full downpour it could become. It still made him wince; he had given Dust everything he wanted so far.  
“Mmmh, you’re tight,” Dust commented in a deceptively lazily tone, twisting the gun and making Killer arch against the wall. “You this pleasing to everyone?”  
Killer opened his mouth to snap back, but the gun sliding free from his body took the words away. It pressed against his teeth and he let it in, feeling the warm, slick metal press against his tongue.  
There was a rustling from Dust, then he grabbed Killer’s femur, finagling him into place with his leg hooked over his hip. Off balance, Killer leaned his weight against the wall. The air was cold on his pussy.  
Dust stroked his dick, then grinded against the wetness leaking from Killer. His dick caught on Killer’s clit and he gasped softly, grinding back against Dust.  
Dust made a pleased grunt. He swiped at the back on Killer’s face and used it to slick up his cock further, the horrible nature of it making Killer’s magic churn.  
When Dust finally decided to quit messing around, he pushed into Killer with a passive-aggressive slowness that bordered on torture. Killer bit down on the gun accidentally, wincing at the harsh grind of his teeth on the metal. Noticing, Dust tilted the gun, pushing down on his tongue until Killer jerked, choking.  
Dust finally stopped moving, seated as far into Killer as he could get. He pressed a hand against the wall, careless with the gun as it pushed into Killer’s throat.  
Killer gagged and turned his head, trying to get it out. He swallowed and tasted iron, felt the grip pressed tight to the edge of his mouth.  
“Shhh,” Dust whispered soothingly. He actually took the gun out, metal clicking against Killer’s teeth. As Killer gasped for air, he smoothed the wet barrel against his face. “You could have just said something.”  
Killer have him a glare that those words deserved.  
The gun was pressed against his hip as Dust used that hand to steady him and pulled his dick almost completely free. He started thrusting into Killer’s heat, some of the insanity fading from his eyes as they hazed over with lust.  
Killer rocked back against him, the sickening feeling easing without the gun pointed at him or Dust messing with the black dripping from his sockets. The ease of tension was enough to get him going fast, and he was already panting for breath, the slide of Dust inside him wet and easy. The target shape between them flickered between its round shape and a hazy heart outline.  
Dust suddenly changed the angle and Killer cried out, clinging to him as he released on Dust, voice cracking. Dust kept fucking him through it and he choked on a sob.  
“LV makes someone numb to killing,” Dust said suddenly. “But did you know it also makes you numb to others’ pain? I’m sure you do, you look like you’ve felt LV. Do you remember it? You still have some, it feels like. Remember the feeling of dust stuck in your joints? The taste of it in your mouth?”  
Killer whined, pressing his forehead to Dust’s shoulder as he continued thrusting, the pleasure surging back up slowly. “Yeah, I remember,” he said weakly.  
“It’s good, huh?” Dust purred against his temple. “The power, being stronger than anyone. Then everyone. You could rip the world apart and rebuild it if you wanted to.”  
Killer shook his head, but words escaped him.  
“Aww, you poor thing. You don’t know how important we are, as Sanses. How crucial. Without us, the world stops. The game can’t go on. But it doesn’t matter, does it?” He gave a particularly hard push that had Killer moaning, unaware of how loud he was. “It restarts. We play again.”  
“Shoot me.” Killer wasn’t aware he had been thinking about it until the words were out. His magic twisted in fear and perverted desire. When Dust looked at him, surprised, Killer looked back. He was serious.  
Dust burst into bright, maniacal laughter. “Shoot you?” he cackled. “The fuck is wrong with you?”  
Killer could feel himself reaching the edge again, quickly. He tightened down on Dust to hear him growl. “Shoot me,” he repeated.  
Dust snorted. He pressed the gun to his leg. “Here?” Then his spine. “Or here?” Then straight up to his erratic soul, the sensation making it falter like a bad tv signal. “Maybe here.”  
Killer didn’t care. It was all the same ending, the same sweet relief. It was building too fast. “Shoot me,” he said again, calm but breathless.  
“Nihilism at its finest,” Dust said, amused. He took the gun away, to Killer’s irritation, and used Killer’s body until he was gasping, then pressed him into the wall, his form a hard line against Killer.  
Killer panted as he felt Dust filling him, staring blankly into nothing with Dust’s teeth scraping against his shoulder. The pressure in his magic was intense. He was so close.  
Dust leaned away and kissed him, Killer whining into his mouth. When he pulled away, he set the gun to Killer’s soul. “See you on the flip side,” he murmured.  
There was a bang.  
Killer felt his body jerk. Even when he looked down and saw the hole in himself, he didn’t feel anything. Shock, maybe, he thought analytically. Dust jerked up into him one more time and the tenuous thread holding him back broke, Killer screaming as he came. It hurt. It felt good. It was numb. He didn’t know anymore.  
His whole body throbbed. Dust stepped back from him, pulling free, and Killer collapsed to the floor. He couldn’t feel his hands or feet. He could see he didn’t have hands or feet. It was cold.  
But it was such sweet relief.  
He closed his eyes.

**Author's Note:**

> List used: https://twitter.com/idek_uggy/status/1178349575725174786?s=21
> 
> Switched watersports for gunplay.


End file.
